Conventionally known is a shank attachment structure by which a shank of a cutter can be attached with a single motion to an arbor whose base end is attached to a drilling device (electrically-powered drill or drill press). In the case of this one-touch shank attachment structure, only by inserting the shank of the cutter into a shank attachment hole which opens on a lower surface of the arbor, the shank of the cutter can be attached to the arbor with a single motion by a fixing mechanism formed on the shank of the cutter and the arbor (see Patent Document 1).
In order to solve the technical problems of the above shank attachment structure, the present applicant has provided a simply-configured shank attachment structure by which the cutter can be detached from the arbor by operating a detachment sleeve with one hand, the shank does not drop off even if something accidentally contacts the sleeve during the rotation of the drilling device, and a coolant (cutting fluid) can be supplied internally (see Patent Document 2).    Patent Document 1: Japanese Unexamined Patent Application Publication Hei 7-9211    Patent Document 2: WO 98/37999